Lamp-locking means



Aug. 17 1926. 1,596,492

L. KULP LAMP LOCKING MEANS Filed April 23, 1924 Jude )7 1.5075? 4 041 Patented Aug. 17, 1926. 1,596,422

E. STATES PATENT QFFICE.

LESTER KULP, OF CHICAGO, ILLINOIS, ASSIGNOR TO KULP THEFTPROOF LAMP COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

LAMP-LOCKING means.

Application filed April 23, 1924. Serial No. 708,479.

This invention relates to lamp locking adapted to be securely cemented upon the means or devices for rendering electric lamp stem or neck 12 of the lamp bulb and the bulbs theftproof and has particular reference threaded shell contact 13,for embracing the to devices of this character wherein the lockbase member 11.

ing mechanism is entirely embodied in the The base member 11 may comprise a cylamp structure and which may be, if desired, lindrical shell contact 14 upon which the used with the ordinary types of sockets or threaded shell contact 13 is loosely fitted. receptacles. The shell contact 14 may be provided with An important object, therefore, of my inone or more struck-u spring dog members 0 vention is to provide an electric lamp so as at 15, which are or the purpose of enmade that it may be inserted into a socket of gaging depressed or inwardly struck porthe usual construction and yet which cannot tions as at 16, formed upon the shell conbe stolen or removed. from such socket until tact 13. after the bulb has become broken. From an inspection of Figs. 1 and 3, it

15 A further object of this invention is to will be observed that when the base member provide means whereby a lamp bulb may be 11 is rotated in a clockwise direction for ininserted into a receptacle member .by turnsorting the lamp into a receptacle the dog ing movement, but such means being dis- 15 will engage the struck down portion or placeable or capable of being rendered ineflug 16 and as a consequence will exert ro- 20 fective upon an attempt being made to retational force upon the threaded shell conmove the lamp from its receptacle by a turntact 13. In this manner, the threaded shell ing movement. contact may be screwed into the receptacle.

Another aim of this invention is to provide Ho ever, hen an attempt is made 9 IOtatP- a thettprooit lamp in which the electrical the lamp in a counterclockwise direction 25 connections do not become broken or disfor withdrawal from the socket, the dog 15 torted when the bulb is tampered with. A upon striking the lug 16 will become discommon difiioulty of devices of this charplaced from its outwardly bent position acter as previously made has been that the and will spring inwardly sufficient to allow electrical connections to the lamp become dethe lug 16 to pass. Thus the threaded shell 30 stroyed upon an attempt being made to recontact 13 'will not be forced to rotate in this move the bulb from its socket. This, of direction with the base member 11. Accourse, results in rendering the lamp useless cording'ly, the threaded shell contact canwhether stolen or not. not be screwed out of the receptacle and as Further objects off this invention comprise a result the lamp is rendered theftproof.

the use of a very simple, durable and inex- The threaded shell contact is permanently pensive construction for the purposes named re ained against longitudinal movemen in which also embodies substantially the minirespect to the lamp by means of inturne mum number of parts and which, if desired, flanges 17 and 18, located at the respective may embody a lamp bulb member of standends of the threaded shell contact 13. The

49 ard construction. flange 17 is adapted to be spun over and to In the accompanying drawing, which ilabut a'fiange portion 19 at the upper edge of lustrates an embodiment of my invention, the base member 11. The flange 18 is adapt- Figure 1 is aperspective view illustrating ed to be spun over a beaded portion 20 the various separated parts embodied in the formed upon the base member near its lowsame; er edge.

Fig. 2 is a central sectional view through From an inspection of Fig. 2 it will be the base of a lamp embodying this-invenobserved that the lower portions of the tion and showing the parts in assembled reflange 18 may be located at a point which lationship; and, I

will be well within the receptacle member in Fig. 3 is a dc ail sectional view of a porwhich the lamp may be inserted. In this tion of the lamp base member and shell conway the receptacle member serves to prevent tact. access to the threaded shell contact member In general, the invention as illustrated and accordingly, this .member cannot be may comprise an electric lamp bulb 10 of turned either inwardly or out of the recepthe standard construction, a base member 11, tacle by tampering, while the lamp is in op 116 wardly through the erativecondition. However, after the lamp as become worn out, the operator may place a canvas or other bag over the glass portion of'the lamp and thereupon break the lamp. is canvas bag will retain the particles of broken glass. Access may then be had to the flange edge 18 for removal of the lamp byiiliers or other suitable tools.

s shown in Fig. 2, the interior of the be filled with a suitable cement as at 21 and the beaded portion 20 will cooperate with the rib 22 on the lamp bulb to securely lock the lamp bulb stein in the cement and within the base member 11.

At the upper end of the base member 11 a center contact 23 may be positioned and held in place by the use of an insulating end piece 24, which is tightly fitted or molded into the upper end of the base member 11. As indicate in F ig. 2, an inwardly directed beaded ortion 25 may be formed in the base memer 11 for engaging and holding the insulating end piece 24.

base member 11 may no center contact 23 may comprise a. disc.

shaped member having a portion of its periphery struck up to form a spring contact piece 26 and with its central portion punched and struck down to form an eyelet at 27 for engaging an opening 28 in the insulation piece 24 and for receiving oneiof the lamp lead wires 29which may be soldered therein. The other lamp lead Wire 30 insulation piece 24 and a perforated lug as inin Fig. 1. The perforated lug may be soldered to icated at 31 31 preferably is positioned in a depression 32 formed in the insulation piece 24 in order that its surface willbc below that of the insulation. This construction will permit the lead wire 31 to be soldered at the perforation in the lug 31, but without causing the parts of this connection to protrude beyond the surfaces of the base member.

In asmmbling the device, the base member 11 including the threaded shell contact 13 may be, if desired, first completely-assembled independently of the lamp bulb. The inner lower edge of the face of the base member 11. may be covered with unbaked cement which is tobe used to fix the lamp bulb in position therein. flhis cement may lead wires may be directly inserted with very little difficulty. After the lead wires are in place, the lamp base may be subjected to a temperature sufficiently high to bake the may pass up I cement, thus permanently fixing the base in position on the lamp bulb stem.

While I have shown and describe-done specific embodiment of m invention, it is understood that I do not dbsire to have any limitations imposed thereupon except as specifically set forth in the appended claims or required by the prior art, since mechanical expedients or e uiva-lents of the variuos elements are intended to come within the scope of my invention.

Having thus described my invention, what claim as new and desire to secure by Letters Patent of the United States, is: i

LAD incandescent lamp consisting of a bulb member, a center contact therefor, a pair of concentric substantially coextensive and cylindrical shell contact members surrounding the stem of said bulb, and fixed against longitudinal movement in respect to each other, the inner one of said shell contacts being secured as by cement to the bulb stem, the outer shell contact being threaded for engagement with a conventional receptacle, said shell contacts being provided with ratchet means preventing rotation of said bulb in respect to the outer one of said shell contacts in one direction only to permit insertion but being ineli'e-c-v tive for removal of the lamp in respect to a receptacle by turning the bulb, and means for. maintaining electrical connection between the filament of the bulb and said shell and center contacts regardless of possible rotational movement of the bulb with respect to the outer shell contact.

2. An electric lamp comprising a bulb, a threaded shell contact therefor, means permanently fixing said shell contact against Illorilg'itudina l movement in respect to said of such rotation.

3. In combination, an enclosure for electrical apparatus, a pair of concentric substantially coextensive and cylindrical shell contacts mounted on said enclosure, fixed against longitudinal movement in respect to each other, the outer contact being provided with means for engaging a conventional electrical receptacle solely by turning movement of said shell contact, the inner one of said shell contacts being secured receptacle by turning said enclosure.

4 In combination, an enclosure for electrical apparatus, a cylindrical shell mounted on said enclosure, said shell being provided with means for engaginga supporting receptacle by turning movement of said shell, means permanently fixing said shell against longitudinal movement in respect to said enclosure, and ratchet means preventing rotation of said enclosure in respect to said shell in one direction only to permit insertion but to prevent removal of the shell in respect to a, receptacle by turning said enclosure.

5. In Combination, an electric lamp member including a bulb, a shell contact and an insulated center contact therefor, meanspermanently fixing said shell contact against longitudinal movement in respect to said bulb, said lamp member being provided with aresilient dog, means on said shell contact for engaging said dog to prevent rotation of said bulb in respect to said shell contact in one direction only to permitinsertion but to prevent removal of the shell contact in respect to a receptacle by turning said bulb, a filament in said bulb, and means for maintaining electrical connection between sai filament and said shell and center-contacts regardless of the rotation of the bulb with respect to the shell contact.

6. In a device of the type described, an electric lamp bulb, a base therefor comprising a metallic substantially cylindrical shell permanently fixed to the stem thereof, and a cylindrical contact embracing said shell and retained against longitudinal movement in respect thereto, said shell being formed with a resilient ratchet dog protruding outardly of the base and said cylindrical contact being formed with a stamped portion for engaging ing rotation of said bulb in respect to said contact in one direction only to permit insertion but being ineffective for removal of the contact in respect to a receptacle by turning said bulb and means for maintaining anvelectrical connection from the bulb to said contact regardless of attempts to remove the bulb.

7. In an electric lamp, a bulb ofi conventional construction, a cap member permanently fixed upon the stem thereof, and a shell contact embracing said cap member and retained against longitudinal movement thereupon'and against rotation in respect thereto in one direction only.

8. In combination, trical apparatus, a pair of concentric substantially coextensive .and cylindrical shell contacts mounted onsaid enclosure and fixed against longitudinal movement in respect to each other, the outer contact being provided with means for engaging a conventional electricalreceptacle solely by turning movement of said shell contact, the inner one of said shell contacts being secured as by cement to the enclosure and formed with a resilient ratchet dog protruding outwardly of the periphery thereof, and said outer contact being formed with a stamped portion for engaging said dog for preventing rotation of said enclosure in respect to said outer contact in one sertion of the contact in respect to a receptacle by turning. the enclosure.

In witness whereof, I have scribed my name. i I LESTER KULP.

hereunto subsaid ratchet dog for prevent an enclosure for elecdirection only to permit 1nv 

